Permanent casting mold



Jun I6, 1925. 1,542,641

C. D. FETTIS PERMVNENT CASTING MOLD Filed NOV- 28. 1924 3 Sheets-Sheet lY lig] Z fave/@4407@ v (29%@ QQ/zzz@ l@ @5W L fm June 15, 1925.

V c. D. PEITTls PERMANENT CASTING MOLD Filed Nov. 28, 1924' s sheets-sheet 2 NNN@ June 16, 1925. 1,542,641

c. D. PETTIS PERMANENT CASTING MOLD kFiled Nov. 28,1924. s sheets-sheet s Patented June 16, 1925.v v

UNITED STATES cLIrToN n.' rains, or NEW vom; N. Y.

PERMANENT CASTING MOLD. -I

Application inea November 28, 1924. serial m. 752,547.`

' 5 of New York, have invented certain new and useful Improvements in Permanent Casting Molds, of which the'following is a specification.

` The inventlon relates to casting iron and' other high melting point metals in repetition or so-called permanent molds. The invention seeks to provide an improved repetition mold of durable construction preferably formed of metal such as cast iron and madeup of several parts or members movable to open and close the mold,'and so constructed and arranged that ample provision is made for the expansion and 'contraction of the parts, for the dispersion of heat therefrom,

and for the escape of air and gases from4 f the mold cavity. A further object ofy the in# vention is to. provide an improved repetition or permanent mold for the casting of brake shoes and to provide convenient means for supporting stiifening backs for the shoes within the mold cavity, and which are embedded or incorporated therein in the casting operation. With these and other objects in view, the invention consists in the features lof improvement hereinafter set forth,

illustrated in the preferred form in the accompanying drawings and more particu larly-pointed lout in the appended claims.

In the drawings:

mold.

Fig. 2 is a cross section on the lines 2 2 of Figs. 1 and 4. l

Fig. 3 is a detail cross section on the lines 40 3-3 of Figs. 1 and 4.

Fig. 4'is a vertical longitudinal section taken on the line 4 4 of Fig. Fig. 5 is a View partially in plan and partially in section on the-line 5-5 of Fig. 4.

Fig. 6 is an inverted plan view of one of the top sections or closure blocks, illustrating the manner of securing the stifening back for the shoe to the top section. n

Figs. 7 and 8 are detail sections illustrating the manner of supporting another fnrm Fig. 1 is a side elevation of the improved) f transverse member 19 having a central han- -dle 20, the unit comprising the connected positions with their inner walls or parting of stifening back for the shoe in the mold cavity. The improved mold, as stated, is particularly designed for casting railway brake shoes, and for that purpose the parts or 5t members of the mold are arranged to form an elongated mold cavity, substantially rectangular in cross section and soarranged that the brake shoe is cast in a horizontal position with its back, on which the center and end lugs are formed, uppermost.

The mold arts or members which form the bottg'm and side walls of the mold `cavity aremounted upon a base 10 provided with upstanding lugs 11, and in which lugs horizontal pivot pins 12 and 13 are mounted.

,Side andend members v14 and 15 comprise hollow, box-like frames or receptacles formed of cast'iron. The vbottom walls of the frames or receptacles are provided with. depending `lugs 16 engaging the horizontal pivot pins 12 and 13, the end members being moun ed on the pivot pins 13, and the Side members both upon the same pin 12 which,

in the preferred form shown, is in alignment with the vertical parting line or plane between the side members.

The frames of each of theside' and end members are provided near their ends with pairs of outwardly projecting lugs 17 which engage circular cams or eccentrics 18, the latter being mounted on pivots having axes parallel to the axes of the respective members. Preferably, each pair of circular eccentrics or cams is formed'integral with a pair of cams being mounted between the upper ends of lugs 21 on vthe base plate and supported thereon by pivot-screws 22.

By operating these cams the side and end members of the molds may be readily and quickly moved to and from vertical closed surfaces in engagement. The parts are sc arranged that as the cams are moved to closed position, the cams 18 approach, but

do not quite freach, dead center positions vertically above their pivots, so that the leverage of the cams on the mold members serves to lock the mold'membe'rs in closed position, making it unnecessary to employ additional clamps vor the like. l To prevent which extend across and engage the top and the flanges I and with their inner vertical l' faces in alignment with .the inner facesof the flanges 30 and 31. 1n the construct1on shown, stiening ribs extend between-the ribs 34 on the cover plates 32. In this way the blocks are removably held in position the accidental opening of the mold members within the end members, with the blocks for 75 the most part out of contact with the walls during the casting o ration, the end members 15 are prefera ly arran ed to .interlock with the side members `to old them in closed position. For this pur ose,- as most clearly shown in Fig. 5, the ames of the end members are provided at their edges with inwardly ro]ecting flanges forming 5 shoulders 23 which cooperate with shoulders 24 upon the side members and provide a safety guard or locke-for preventingv the opening of theside members until after the end members are opened. Preferably, the

[opening movements of the side and end members are limitedrespectively by pairs-of lugs 25 and 26 formedupon the base l() and cooperating with the lower lugs 17 on the members. Preferably, as shown, the lugs 26 which limit the movement of the side members are considerably higher than the lugs 25 which arrest the end members in open' osition, so that the opening movement o the Ano side members is considerably less than that of the end members. The latter, of course, must be moved Vto a suflicient extent to clear the cooperating safety or locking shoulders 23 and 24, but the side membersneed only be opened sufiiciently to move their inner cavity forming walls away from the finished casting.' The inner walls of the side and end members which form the walls of the mold cavity are'divided into .a number of sections so arranged as to permit the expansion and contraction of the sections as they are heated' and cooled, and the escape of air. and gases from the mold cavity. For this urpose the inner walls of'the hollow side ang endmembers are each formed of a series of hollow, open-backed metal blocks preferably of cast iron, each comprising an inner. wall 27 and outwardly proJectin top, bottom and side flanges 28. The bloc s in the e'nd frames 15 are superposed and the inner walls thereof areprovided with recesses or -seats 29 enrower and has a downturned flange 4l at its inneredge. The flanges 39 and 41 engage seats 42 formed in the upper and lower edges of the side blocks or sections and retaining back plates 43 secured to the outer faces of theside members have longitudinal ribs 44 which extend across and engage the side flanges of the blocks and hold them snugly in engagement with Athe faces of the edge flanges 39 and 41. When thus held in position, portions of the side sections or blocks are flush with the abutting faces of 4 the flan es 39 and form portions of the parting sur aces of the two side members. The remaining portions of the inner walls of the blocks form the bottom and side walls of the mold cavity, which, in the present construction conform respectively to the arched face and side walls of a brake shoe. It is noted that while these side blocks or sections are all substantially the same height, the inner abutting portions progressively diminish from the center towards the ends of the side sectionsl in correspondence with the curvature of the face of the shoe. lar construction shown, the end walls or flanges 36 of the side frames `are spaced somewhat from the ends of the frames and In the particuportions' 45 which extend beyond these flanges to the vertical parting surfaces at the ends of the side members. Like the retaining or back plates of the end sections, the plates 43 are connected by screws to lugs 33 formed on` the outer edge portions of the side frames, and stiff'ening flanges extend between the flanges v44.

The retainer plates 32 and 43, and prefarably, also the side walls of the end members and the bottom walls ofthe side members,are lprovided with openings '46 for the free circulation of air through the members and about the blocks or sections and thereby aid inBpreventing the overheating of the blocks. urthermore, the construction of the blocks with their inner walls 27 of sub- ',stantially uniform thickness and their outwardly projecting, stiiening flanges 28,

which are 'preferably' relatively thinner, is such that rshile the blocks are quite stiff and rigid, heat is readily dispersed there- ,from and they are not subject to excessive' strains, due to unequal heating and cooling of different portions thereof. It is particularly noted that the inner walls, which,

as stated, are ofA substantially uniform' thickness, should be suiiiciently thin. '-to readily dissipate the heat to which they are subjected and avoid the development of strains due to unequal heating and cooling.

` On the other hand, these walls should be suiciently thick (preferably about of an inch in the present construction, where it is designed to cast a railway brake shoe) to avoid distortion or warping. v

It is also noted that the dividing of the `inner wall of ea ch' of the mold members into .separate blocks or sections avoids the transmission of strains due to -the heating and cooling throu hout the extent of these walls D t f as would be t a single piece.

Ample provision is also made for the eX- ansion and contraction of the individual locks or sections. y,For this purpose, the blocks are of such dimensions that they do not snugly fit between thev edges of the flanges at the -inner edges of the side and end frames or receptacles. Thus, the length of one of the series of blocks'in `each side uul member is slightly less .than the length of the mold cavity. In the present construction, that is designed to cast a brake shoe of the standard size', the combined width or length of the series of blocks in each side frame is preferably about 116 of an linch less than the len h of the vmold cavity, so that the series o blocks (seven in number in the construction shown), fit* loosely between the end walls or flanges 36kof the side frames. There is also a cll'earance pref? erably of about El; of an inch between the shoulder seats of each block and the edges of the flanges 39 and 41 between which they fit and there is a similar slight clearance betweenthe blocks in the end frames and the edges of the flanges 30 and 31'. It is also noted that while the blocks are snugly held in position between the ribs o1' retaining back plates and the faces of the inner edge.

flanges, they are otherwise for the most part held out o f contact with the walls ofthe receptacles or frames. This larrangement aids in permitting the expansion and contraction and the' limited adjustment of the-individual blocks or sections without warping or distortion of the parts of the mold. Not only is the construction such that dise case if they were formed o tortion and injury of the parts of the'mold due to heating and cooling are avoided, but

ribs of the retainer back plates and the faces of,V the edge flanges, so Vthat when brought to closed 'position the blocks will engage sufficiently snugly at the vertical parting surfaces between the side members and between the latter and the end members "to prevent theescape of molten metal from the mold cavity.

vVVhen'closed, the side and end members form a horizontally elongated, open-topped mold'cavit conformingin the present in' stance tot eface, side and end walls of a brake shoe, and it is-noted that these membersform in effect a multi-part drag. In the present construction, the use of a member like the ordinary cope for forming the top 'wall of the mold cavity, is avoided.

Instead, a number of small, ea 'ly handled separate sections adapted to be etachably .supported on the drag'members,\are used.

In the mold shown in Figs. l to 5 inclusi-ve,

the closure for forming the top of the mold cavity comprises two end sections and an intermediate central section, all preferably formed of cast iron. The central section is preferably formed of two end blocks 47 and two intermediate blocks 48. `These blocks are arranged side by side and fastened together by bolts 49. The end sections 50 and 51 vare entirely separate from the center sec- `tion and preferably one of these sections,

for example the section 50, is formed of two like parts having vertical parting faces extending longitudinally of the mold, thesefaces being recessed to form a pouring gate 50". `All of the top or closure sections are rovided on' their outer side walls Awith pro- '.)ections orribs 52 which preferably form continuous'slioulders having fiat, horizontal lower faces' that engage the inner edge por tions" of the top walls of the side andend `-members;A Each of the top sections also comprises 'a portion which .projectsdownwardly below the shoulders or ribs 52 and fits between the upper portions of the inner vertical faces of the drag members when the latter are closed. These depending portions, or atleast the extreme lower parts thereof are of substantially the same width as the mold cavity and extend below the upper edges of the blocks or sections in the side members. The lower surfaces of the closure also, theseblocks are recesse ends of a sand core 54 for forming the openblocks or sections conform tothe arched top of the mold cavity, but it is noted that the parting surfaces between the top closuresec- '.tions andthe other members of the mold-are flat. i

The lowerfaces ofthe end blocks or sections` 50 and 51 are provided with suitable recesses 53 which form the end, lugs on the back ofthe brake shoe, and the blocks 48 of ,the central sections-have recesses for forming the center attaching lu Preferably, to'receive -the ing inthe attaching lug and also, 1n the nar- 2o' i .48 and 4'( of the center section, areV provided ticular form shown, these blocks are shed to' receive a reinforcing steel lug 55. Y ,is U-shaped steel lug as usual is arranged to engage a strengthening steel back 56 having lon tudinalslots 57 therein. To hold the bac place the meeting faces of the blocks with thin grooves or slits that receive two thin, fiat, metal attaching cli s 58. These clips 'are adapted to bepasse through the grooves in the center section and the slots 57' of the back 56, and have offset lower ends 59 forengaging the inner face of the back. The upper ends of the clips are adapted to be bent into engagement with the upper face of the center closure section and `so clamp the;

back snu ly against its'lower face.` The clips frietlonally lit the grooves of the center closure section and snugly fit the inner ends of the openings 57 ofthe back so -that the latter is accurately positionedl in the mold cavity and snugly held against the top wall thereof. It is also noted'that the top or closure sections fitting as'they dowithin the upper portions of the movable side and en'd members, are accurately positioned- ,or centered when the members are closed.

As an aid in positionin the closure blocks and also to securely hol them against displacement, the upper walls of the side members are provided with lugs 60 adapted'to overlie the ribs or shoulders 52 `formed on the' closure sections. Preferably the meetin' `faces of the shoulders and lugs are inclin as shown, so that they may be brought into snug contact when the side members are closed. When the side members are in their open position as determined by the` stop lugs 25, the lugs 60 are of course moved i away from vthe shoulders 52 .so that the clocan be readily and quicklly sure sections may be readily placed in or removed from position, but in this extreme open position, the shoulders 52 cannot clear the upper-'inner edges of the side members and hence cannot .be dropped or fall into the mold cavity. Therefore, when .the mold members are open the top or closure sections p placed in position and are automatica y centered and locked in proper position when the side members are moved and locked in closed position by their operating cams 18. Then, when the end sections are similarly moved to and locked in closed position by their oper- 'i ating cams,.the shoulders 23 thereof overlie the shoulders 24.0f the side sections, as prevlously noted, and act as a safety lock to f prevent the displacement of the other mold parts until the end members are again open. To vprevent the .escape ofmolten' metal from between the'parts of the end section 50, .theI meeting faces thereof are provided on opposite sides of the pouringgate with vertical matching ribs-and grooves 6l. By dil I viding the center section vinto separate blocks,

the grooves for the attaching clips 58 and the recesses for forming the center lug and for receiving the core an'd vcenter lug rein-- forcement can be readily formed in the different blocks before they aresecured together. It isalso noted that the grooves vwhich receive the attaching clips intersect 'the recesses which receive the ends of the core 54, and these grooves thus form vents for the core. Also, to permit the escape of air and gases from-the upper portion of the recess that forms the center lug, the meeting faces of the blocks 48 are provided with venting grooves 62.. These blocks also, referlably, have projecting eyes 68 by whlch the center section and finished Ilshoe can be removed as lsoon as the mold is opened. By

forming the top closure of small, separate sections, they can be readily` handled and placed in and removed from position. Furthermore, the dimensions of these sections are such that narrow venting spaces of? preferablyabout 1/100 of an inch, are formed between them and permit the escape of air and gases from the mold cavity, but do not allow the passage of molten metal. Thus, inV

contraction and limited adjustment of the closure blockes and alsoprovides for free venting of the mold cavity. At the same time, the closure sections can be easily and uickly placed in and removed from position, are accurately centered between the side and end members when the latter are closed and the joints at the parting surfaces, while .permitting venting, are sufficiently snug to be metal tight. y

In the present construction, the recess for forming the center lug in the center closure section, has a widthat its lower portion the same as that of the shoe and for this reason the center section is somewhat wider than outer faces.

tions and 'effect a more rapid dissemination of heat therefrom, they may be made hollow or provided with depressions 64 inA their It is also noted that the-end blocks 50 and 51 are of the same size so that they are interchangeable and preferably, in practice, the position of these blocks is changed at each operation so that Vthe different portions of the mold are subjected at successive pourings to the high heat of molten metal entering the mold through the pouring gate.

At each operation the faces of the mold sections or blocks are cleaned and preferably provided with a suitable protective coating. These operations are facilitated since, in open position, the upwardly and outwardly inclined mold faces are exposed. Then after attaching the back to the center closure secn n another.

tion, it, together with the end sections, are

placed upon the side members, the latter and the end members closed in the order named and the .molten metal poured into the mold cavity. Preferably, as soon as the molten metal has set but before it has `contracted to any extent, first the end and then at least' one of the side members are opened so that the walls thereof are swung out of contact with the casting, it being noted that the arrangement is such that in this opening move` the end closure .sections 50 and 51' are re# moved. But even if 'this is not done, the

bringing together of these end lugs by the"A contraction of the casting will tip or tilt the* end sections 50 and 51 so that there will be no strains or rupture developed either in the casting or in the closure sections, because the latter are free to move relatively to one 4 Then when the casting has contracted sufliciently to free the center lug of the shoe from the intermediate closurel section, it can be easily disconnected therefrom by bending 'the upper ends of the vclips 58 so that they can be withdrawn from the grooves in the center closure section. n

The improved mold may also beemployed` for casting a brake shoe having. asubstantially continuous strengthening steel back or shell, as shown in Figs. 7 and 8.v This particular steel back or shell shown in these figures is provided with la. down* l course the passage of molten metal therethrough from the pouring gate, and with openings 69 to permit the passage of metal into the end lug cavities 53 of the end closure blocks or sectlons 50 and 51. In casting a shoe of this type, the center closure section omitted. Instead, the shell, rwhich\ forms the top wall of the mold cavity, is held in proper kposition preferably by means of one or more vtransverse members `or `bars `70 adapted to rest upon the upper edges of the side 'members and are provided with laterally projecting lugs' 71` adapted to engage the center lug on the back of the shell. Preferably, the upper faces of these lugs, are cam-or wedge-shaped so that, as4 they are forced' into the upper portion of the center lug, they will draw the shell snugly up into engagement with the lower faces of the end blocks or -sections 50 and 51 and form metal tight joints therewith. For'convenience, ifdesired, the members 70 may be provided with arms 72 connected by a pivot pin 73. To provide good metal tight joints between the steel back or shell and the sidev members of the mold, and also to aid in lholding .the shell in place, the latter is made of such width that it is gripped between the side Ymembers `when the latter are closed.

iThus for a standard passenger car brake shoe, the shell is preferably made gli; of 'an inch wider. than the mold cavity,v and it will yield slightly when the side members are brought to closed position.

. FigLS ,illustrates the manner of positioning a steel back or shell and an insert in -`the mold comprising a number of superposed layers of expanded metal which are cast into the face portion of the shoe. These layers are bound together at spaced intervals by wires'\76, the upper portions of which are twisted together and provided with laterally projecting portions 77, the

ends 78 of which are arranged to fit within,

theL downturned edge flanges of the steel shellor back. In this way the insert and steel shell may be connected together and placed vas a unit within the mold 'and the connected parts will 4serve to properly position each other during the casting operation. That is tov say, the insert connecting wires will assist the positioning of theA shell in the mold cavity and the shell, which is of revented `from rising by the .end closure locks, will in turn hold-the insert in proper positionyin the lowerportionof' the mold cavity. When the moldis used as illustrated in Figs. 7 .and 8, the joints between the back or shell andwthe mold members'are suiciently tight to prevent the v passage-of molten metal, but they are not and cannot well be made air and gas tight, so that ampleerovision is made forthe venting of the -mold.

'In the improved mold, the Walls of the cavityfor matrix are sectionalized and the y metal sections yso arranged. and supported that each can expand independently of the l0 others, thus localizing strains dueto heating and. cooling. 'Furthermord excessive `heating and distortionof the metal parts of the mold is prevented bythe provisionfor the circulation lof air through the hollow frames 15 or receptacles and about the blocks, by the- `formation of the mold into separable parts or members, so that the casting can`be readily -and quicklyiremoved from contact with the walls of the mold cavity, as soon as it is set, and particularly by the described construction of the hollow, box-like frames 1 and hollow mold -sectionsor blocks, the walls of which are quite thin and present large surface area for the rapid radiation 25 of heat.- In 4this connection it is noted, that,

while the individual blocks are quite rigid,

` the walls of-the framesor receptacles in the yparticular construction described `are, for the most part, preferably only 1/1 ofan inch thick solthat,theyiare slightly yielding or flexible and will absorb strains due to the expansion ofthe parts of the mold r withoutpermanent distortion or rupture.

Also, as an aid in vavoiding distortion, the

* edge flangesof the-frames, which position the blocks and are preferably thickened,I are provided at intervals with transverse slits 79 as described mostV clearly in Fig. 5.

As previously pointed out, clearance is l 40 j provided between. the blocks that form the inch. Indeed the metal blockslinthe frame members and the top closure blocksA can be placed lin position side by side with their adjacentY walls loosely contacting. Never` theless, because of the clearance allowed and the'limited freedom of adjustment permit-- ted, the'joints betweenthe blocks-or sectionsV and between lthe mold parts, while -sufficiently tight to prevent the escape of molten metal and the formation of fins that would G0 interfere' with the ready removal of the f castings, permit the expansionof the parts and the free venting of the gases from 'the mold cavity, The attainment of these advantages is affected or-aided by forming the receptacles and blocks of. cast iron, by

'qnickly cool, that it is extremely difficult to tachable from one another and from the :eMac/sa clamping the blocks so that they cannot move laterally to and from the vertical parting surfaces of the pivoted side and end members of the mold, and by the construction and arrangement of the metal closure blocks or sections. In this connection it is noted that the closure blocks t between the 'upper portions of the inner vertical walls of the side and end members and are provided with shouldersthat rest on the upper edges of the mold members, so that good joints are formed between. the `flat. vertical and horizontal faces of these parts, when the mold is closed. It is also noted that the depending portions of the closure blocks,

so?, in the form shown in Figs. l to 5 inclusive,

.and the edges of the back or shell in the forms shown in Figs. 6 and 7, cover the 'joints betweenthe upper ends of the blocks in the side members and the upper edge flange members 41, so that the formation of fins between these parts is prevented. The formation of good metal tight joints between the several parts of the mold is also aided by the construction and-arrangement of t'he opening and closing cams 18 andthe interlocking shoulders and lugs 52 and 60 of the closureblocks and side members, all of'which serve to press the mold parts into engagement. l\lotwithstandinr the fact that 9D the mold, as stated, is made of al number of parts, so that the casting as soon as it is set can be readily disengagedfrorn contact therewith, provision is made whereby the parts can be quickly opened and ,closed Yand '10U ,interlocked in closed 'position without the t'ild of supplemental clamps, screws or the While the vemployment of permanent molds forthe casting of brake shoes has been heretofore many times attempted, it/ has beenfound that because such 'castings are thick and heavy and do not readily anddo so, and at the'present time practically UU all brake shoes are Vmade in sand molds.

However, for the reasons above noted, the present improved mold is well adapted to the successful and rapid operation of the castingv of brake shoes. It is particularly notedth-at `the use of the mold for castingbrake shoes is facilitated by the arrange! ment of the'pivoted side and end members forming a closed` and open-topped cavity that conforms to the face, side and end walls of the brake shoe, and a closure detachably mounted on these members fitting within the same and forming the back of the shoe and center and end lugs thereof. As already noted, by forming the closure of sections that are. entirely separate and deother kmembers of the mold, they canA be readily disengaged from the irregular back face` ofV the shoe. The closure also, as

as defined in the claims.

. in position,

. by side i flanges of said blocks,

I claim as my invention:

1. In fa permanent mold for castings, mold members movable to and from closed position and'v each comprising a box-like metal frame or receptacleand a series of hollow metal blocks 'arranged side by side therein and each comprising side flanges and an inner wall forming a portion of the niold cavity and a portionof the'parting surface of the mold member, said :traine having means engagingv a wall of said and a removable plate provided with means engaging the flanges of the blocks to re# niova'blyfhold the latter in position, substantially as described.

2. In a permanent mold, mold members movable to and from closed. position and each comprising aframe and a series of hollow backed `metal blocks forming at least part of the mold cavity, said 'frame having openings free circulation of new air about the blocks, substantially as described.

3. In a permanentinold for iron and like castings, mold members movable to- -and from closed position and `each comprising a box-like metal frame or receptacle and a series of hollow metal blocks arranged sideby sidewithin said frame and each comprising side flanges and an-inner wall forming al portion of the niold cavity and a portion of the parting surface of the mold member, said frame having inner edge flanges en aging the .inner vwalls of said blocks an a removable back plate provided With ribs engaging the side flanges of the blocks to removably hold the latter substantially as described.

4. In a permanent mold for iron andlike castings, mold members movable to and from closedl position and each -comprising a box-likemetal frame or kreceiiitacle and a series of hollow metal blocks arranged side within .said frame and each comprising side flanges and an inner wall forming a portion of the mold cavity and a portion of the parting surface of the `mold member, said blocks having recessed seats -at the opposite edges of their inner walls and said frame having inner edge flanges engaging said seats and removable back plates providtd with ribs ernl :aging the side y substantially as described. f

5. In a permanent `mold for iron and like castings, ,mold members movable to and from closed position and each comprising blocks,

through its walls for the a series of hollow metal blocks arranged side by-side Within said frame and each comprising side flanges and an inner wall forming a portionof the mold cavity and .'a portion of the parting surface of the inold member, said vblocks having rec ssed seats -at their opposite edges of their inner walls, said frame having inner edge flanges engaging said seats and removablebacl; plates provided with ribs engaging the side' iianges of said blocks, and said frame having opeiia box-like .metal frame or receptacle and ings for the circulation of air about .the

blocks, theparts being arranged to permit the expansion of the block and the escape of gases between the same, substantially as described.

6. In a permanent mold for iron and like castings, a base, a plurality of mold niembers pivoted on the base from closed position and comprising metal-..-V

frames and a series of hollow, open-backed, metal blocks arranged side-by side within eachv of said frames and adapted to abut in the closed position of the mold members to form the mold cavity, said frames having openings in their walls to permit the circulation of air about the blocks and having means for removably holding the blocks in positiontherein and in a manner permitting the expansion of the blocks and the escape of gases between the same, substantially as described. A

7. In a permanent mold, mold members movable to andfroin closed position and each comprising a frame and a siries of hollow metal blocks forming at least part of the mold cavity, said frame having openings through its wallsin dierent horizontal planes for the free circulation of new air about theblocks, substantially as described.

8a In apermanent mold for casting brake shoes andthe like, a pair of movable side members eaclr comprising a metal frame and a seiies of hollow metal blocks arranged side by side within the frame in a series extending longitudinally thereof and of the mold cavity, said blocks having inner walls 'of/substantially uniform thickness Jforming the parting surfaces of said side members and the bottom and sides of the mold cavity and each block having relativelyl thinner side walls, and seats at the upper and lower edges of its inner Walls, and said frames having flanges at their upper and lower inner edges engaging the seats of said'bloclrs and removable back plates provided with ribs engaging the side flanges of the blocks, substantially as described.

9. In a Apermanent mold for casting brake shoes and the' like, a base, a plurality of mold members movably mounted on said base and comprising box-like metal frames having inner edge iianges and removable -back plates and a series of hollow izo to move to angl 85kg metal blocks arranged sideby side within nally thereof and of the mold cavity, submovable to and from position ina manner sion of the blocks,

-side and end walls of an .flanged metal blocks,

Vlow metal blocks,

each of said frames and having inner walls of substantially uniform thickness and out wardly projecting side flanges, the inner walls of the blocks being arranged to abut in the closed position of the mold members and having portions forming the bottom, elongated mold cavity, said walls. having shoulder seatsat `their-upper and lower edges engaging the mner edge flanges of said frames and said back' plates having ribs extendingacross and engaging the outer edges' of the side anges of the blocks saidv frames having openings in their wal for the circulation of air about'theblocks and the dimensions of the frames and blocks permitting the -expansion and, limited adjustment of the blocks and the escape offgases between the same, substantially as described.

10. A permanent mold Vfor casting brake shoes having a horizontal, elongated mold cavity substantially rectangular in cross sec- .tion and comprising a base, side members pivotallymounted lon said base, a longitudinal series of metal sections removablymounted in each of said members wall having portions of substantially uniform thickness forming part of the bottom andone of arate metal members formingthe ends of the cavity andametaI closure adapted to be detachably mounted on saidside and end 'mem bers and forming the top of the mold cavity, substantially as described.

l1. Ina permanentmold, mold members closed position and a frame and aseries of said frame having means loosely engaging the -langes of said blocks for removably holding the same in permitting the expaneach comprising 12. In a permanent mold, mold members movable to. and from closed position and each comprising a frame and a series of holsaid frame having means loosely engaging said bloclrscfor removably holding the same in position in a manner permitting the expansion of the blocks While K maintaining a constant overall mold cavity length, substantially' as described.

. 13. In a permanent mold, a pair of movable side members each comprising a frame and i series of transversely divided hollow metal blocks loosely arranged side by side within the frame in a series extending longitudinally thereof and of the mold cavity, substantially as described.

14. In a permanent mold, a pair of movable side members each comprising a frame and a series of transversely dividedhollow4 metal blocks arran ed side by side within the framel in a series extending longitudig and con! stituting the inner walls thereof, each such` the sides-of the mold cavity. sepstantially as described.

15. I na permanent mold, mold members movable to and from closed position, each mold member comprising a frame and a series of hollow metal blocks forming a common cavity and loosely carried thereby for floating movement under expansionr substantially asdescribed.

16. In a permanentmold, mold members movable to and from closed position, each member comprising a frame and a seriesof hollow metal blocks carried thereby, said frame being constructedto permit move- -metal blocks, and means loosely supporting substantially as described.

` having a molding cavity, anda closure for said blocks to permit expansion vor contraction thereof without changing the over-all dimensions of the molding surface, sub-4 stantially asdescribed.

18.. As an article of manufacture, an openable casting mold'having at least a portion of its molding surface formedof a plurality of adjacent relatively movable hollow metal blocks, and means loosely -supporting said blocks to permit relative floating movement thereof, substantially as described.

' 19. As an article of manufacture, a casting mold having at least a portion of-its y molding surface formed of a plurality of adjacent relatively movable hollow metal blocks, `and means loosely supporting said.

blocks, said means' providing passages behind vthe blocks for the free circulation of air against the backs thereof and having openings to the atmosphere providing free 4 circulation of air to said tially as described.

20. As an article ofmanufacture, amold passages, substansection and filler section, substantially as described.

23. The method of forming castings, cornprising'l pouring successive castings from .opposite ends of the mold, substantially as described.

24.-l The method of forming'castings, oomthe ste-p consisting of maintaining a more prising reversing the position of thel pournearlypuniform average mold temperature, liv.

, ing gate after at least certain of successive comprising initially delivering the molten casting operations to thereby deliver the metal to diiferent portions of the mold for molten metal initially to different portions successive casting operations in the same of the inold cavity, substantially as `(lemold, substantially as described.

' scribed.

'25. Intlie method of repetition castings, 1 CLIFTON-D. PETTIS. 

